92 CC DS Gas Hairline Crack in Transmission

[David Crum]

I picked up a 92 Gas Club Car DS back in November. The cart runs great. I have a 6" Jake's A-Arm lift on it and 23" tires. The only "grinding" that I notice is when the cart is not running and in neutral, if I push the cart forward and backward, I hear a grinding coming from the back end.

I noticed a leak under the differential housing. started from the top and pulled the driven clutch off, then the transmission. It turns out that the transmission has a hairline crack next to the nut on the backside of it. I have Lucas 80w90 gear oil in both transmission and diff.

My questions are:
1. What could cause this crack?

2. Should I worry about it?

3. What could I do to repair it?

Any help is greatly appreciated.